U.S. Water News Online
SACRAMENTO, Calif. -- The California Department of Water
Resources (DWR) has begun a two-year study to document the effects of
using gray water for home landscaping systems here.
The department is working with several local water districts to
install gray water systems at single-family homes -- 10 have been
selected across a range of modest to affluent neighborhoods in the
district -- to document water savings, analyze customer satisfaction,
and determine the effects of gray water on the landscape.
According to Marcia Prillwitz, Landscape Program Manager at DWR
who is in charge of the Gray Water Program, the use of gray water for
landscape irrigation purposes has been legal in California since
1994, but so far its use has been limited to single-family dwellings.
DWR, she says, is planning to expand their current Gray Water Guide
-- a practical manual on how to set up such a system -- for
multi-family, commercial, and industrial users.
"We are currently revising the regulations for this purpose," said
Prillwitz. "We expect the new regulations and guide book to be
available by January of 1997."
Under the program, a family or housing unit uses its own
wastewater -- excluding sewage -- to irrigate its own landscape, thus
reducing water consumption and saving considerably on water
The two-year study, which began this July, should for the first
time give DWR statistics on gray water use -- its benefits, cost, and
effect on soils and plants. It will help answer such questions as,
how much gray water is generated by a family, and therefore how
efficient and effective the entire system is.
Prillwitz says that investment in a gray water system for
residential use can cost anywhere from $500 to $5000, depending on
the sophistication of the system installed. The participants in this
study are getting some financial assistance from DWR, as well as
their local water district, to install the system.
Since participants range from owners of modest to more affluent
dwellings, she said, the range of systems should be great enough to
get an accurate sampling of system types and document the comparative
"We hope this will give us a better idea of the benefits different
systems can offer," she said, "as well as the benefit -- and cost --
of the gray water system itself."
Prillwitz says other states, including Texas, Arizona, New Mexico,
Oregon, Washington, and Florida are currently looking at such gray
water programs, but they have yet to legalize its use.
In California, she said, there are already a couple of companies
specializing in gray water technology, but, she added, "we wish there
were more." As the practice becomes more common, she said, the
manufacturing base will no doubt grow.
For a copy of DWR's Gray Water Guide write to:
Marcia Prillwitz, Landscape Program Manager Calif. Department of
Water Resources Central Records 1416 9th St. Sacramento, CA 95814
e-mail address: MarciaP@water.CA.gov
Return to the U.S. Water News Archives page
Return to the U.S. Water News Homepage